Plasma processing apparatuses for processing semiconductor substrates, such as semiconductor wafers, can include one or more gas distribution members through which gas is flowed into a plasma processing chamber. For example, the gas distribution member can be a component of a showerhead electrode assembly positioned in the chamber to distribute process gas over a surface of a semiconductor substrate being processed in the chamber. Current gas distribution members are constructed from brazing two aluminum surfaces together and anodizing the aluminum surfaces, however, overflow of the brazing material is susceptible to corrosion when using halogen gases which may lead to contamination of semiconductor wafers during processing. Therefore a corrosion resistant gas distribution member is desired.